1、第九章 助動詞與情態(tài)動詞9.1 助動詞的含義和功能助動詞本身無詞義,它僅僅是用來幫助主要動詞構(gòu)成各種時態(tài)、語態(tài)、語氣以及否定和疑問結(jié)構(gòu)。1）由be，have，shall(should)，will(would)構(gòu)成除現(xiàn)在一般時和過去一般時外的全部時態(tài)。如：（1）I shall be here any minute. 我將隨時到達(dá)這里。（由shall構(gòu)成將來一般時）（2）The train is now rapidly approaching the city of Beijing. 火車現(xiàn)在正迅速臨近北京城。（由is構(gòu)成現(xiàn)在進(jìn)行時）（3）We shall be having rain, rain

2、, and nothing but rain. 我們會有沒完沒了的雨。（由shall be構(gòu)成將來進(jìn)行時）（4）The roads were full of people. We hadnt foreseen that. 路上都是人。這是我們事先未料到的。（由had構(gòu)成過去完成時）（5）Soon they would have reached their time limit and must return to the camp. 不久規(guī)定的時間就要到了，他們就得回營地了。（由would have構(gòu)成過去將來完成時）（6）He has been scoring plenty of goals

3、 this season. 在這個（足球）賽季里，他踢進(jìn)了許多球。（由has been構(gòu)成現(xiàn)在完成進(jìn)行時）2）由be構(gòu)成被動語態(tài)。如：（7）One is not guilty until he is proved. 在沒有證明有罪之前，人都是無罪的。（現(xiàn)在一般時的被動式）（8）She almost felt that she was being mocked. 她幾乎感覺到她在被嘲弄。（過去進(jìn)行時的被動式）（9）I suspected that I had been followed and watched since I arrived in London. 我懷疑我到倫敦以后就已被跟蹤和監(jiān)

4、視。（過去完成時的被動式）（10）I know he hates being interrupted. 我知道他不喜歡別人打斷他的話。（動名詞的被動式）3）由had，should，would，should have，would have等構(gòu)成各種虛擬語氣。如：（11）If I had Jims build, Id go out for the wrestling team. 假如我有吉姆那樣的體格，我早就去參加摔跤隊了。（12）The soup wouldve been better if it had had less salt. 假如少放點(diǎn)鹽，這湯會好喝得多。4）由do構(gòu)成現(xiàn)在一般時和過去

5、一般時的疑問結(jié)構(gòu)。如：（13）When do you meet again? 我們什么時候再見？（14）Did you know the hot dog did not originate in the United States, but in Germany? 你知道“熱狗”不是來源于美國，而是來源于德國嗎？5）由do+not構(gòu)成現(xiàn)在一般時和過去一般時的否定結(jié)構(gòu)。如：（15）Dont knit your brow like that. 別那樣皺眉頭。（16）We didnt think wed be this late. 我們沒想到我們會到得這么晚。當(dāng)兩個或兩個以上包含相同助動詞的謂語動詞

6、并列時，后面的助動詞通常省略。如：（17）The letter will be typed and sent off immediately. 這封信將立即打好并發(fā)出。（18）Having explained the rule and given a few examples, the teacher asked the students to write some exercises at home. 教師在解釋完規(guī)則并舉出幾個例子后，要求學(xué)生回家做一些練習(xí)。助動詞在句中一般不重讀，但當(dāng)它代替前面的動詞或強(qiáng)調(diào)動詞的意義時則應(yīng)重讀。如：（19）Do you speak English? 你會說

7、英語嗎？Yes, I do. 是，我會說。（20）But I have done it. 但是我把它干了。9.2 be的形式和用法助動詞be有八種形式：肯定式 縮略肯定式 否定式 縮略否定式原形 be 現(xiàn)在式第一人稱單數(shù)I am m am not arentm not現(xiàn)在式第三人稱單數(shù)he，she，it is s is not isnts not現(xiàn)在式第二人稱單、復(fù)數(shù)和第一、三人稱復(fù)數(shù)you，we，they are re are not arentre not過去式第一、第三人稱單數(shù)I， he，she，it was was not wasnt過去式第二人稱單、復(fù)數(shù)和第一、三人稱復(fù)數(shù)you，we

8、，they were were not werent現(xiàn)在分詞 being not being 過去分詞 been not been 注在英國英語中，arent使用很廣泛。在美國英語中使用較多的是被認(rèn)為非標(biāo)準(zhǔn)的aint。助動詞be主要用法是：1）與現(xiàn)在分詞構(gòu)成各種進(jìn)行時態(tài)以及與have和現(xiàn)在分詞構(gòu)成完成時態(tài)。如：（1）Fear of crime is slowly paralyzing American society. 犯罪恐懼癥正逐漸地使美國社會陷于癱瘓。（2）The telephone had been ringing for three minutes before it was ans

9、wered. 電話鈴響了三分鐘才有人接。2）與過去分詞構(gòu)成被動語態(tài)。如：（3）He was an ardent fighter for freedom and independence. He was loved by millions and hated only by a handful. 他是個爭取自由和獨(dú)立的熱誠戰(zhàn)士，為成百萬人所愛戴，為僅僅一小撮人所仇恨。（4）They came to Europe where their mother had been educated and stayed three years. 他們來到他們的母親受教育的歐洲，并待了三年。此外，be還可用作連

10、系動詞。如：（5）It was one of the happiest afternoons he had ever spent. 那是他有生以來最愉快的一個下午。詞組be to有情態(tài)意義，詳見“情態(tài)動詞”。9.3 have的形式和用法助動詞have有五種形式：肯定式 縮略肯定式 否定式 縮略否定式原形 have ve have not havent ve not現(xiàn)在式第三人稱單數(shù) has s has not hasnts not過去式 had d had not hadntd not現(xiàn)在分詞 having not having 過去分詞 had 助動詞have的主要用法是：1）與過去分詞構(gòu)成

11、各種完成時態(tài)。如：（1）Newton has explained the movements of he moon from the attractions of the earth. 牛頓闡明了月球受到地球引力而運(yùn)行的規(guī)律。（2）Reluctantly, she opened the door, she had not kept it locked; there had been no need. 她勉強(qiáng)地開了門。她沒有鎖門，也沒有必要鎖門。2）與been+現(xiàn)在分詞構(gòu)成各種完成進(jìn)行時態(tài)。如：（3）Men have been digging salt out of it for six hun

12、dred years, and yet there seems as much left as ever. 人們在這里掘鹽已六百年，但鹽似乎還是那么多。（4）In another months time Mr. Henry will have been teaching here for exactly thirty years. 再過一個月，亨利先生就將在這里從事教學(xué)整30年了。此外，have還可用作實義動詞，意謂“有”、“吃”等。如：（5）Bad news has wings. 丑事傳千里。（6）Youre anaemic, you must have some iron. 你患貧血癥，應(yīng)

13、該服一些鐵。have還可用作使役動詞。如：（7）We now have the problem solved. 我們現(xiàn)已把這個問題解決了。（8）I had a tooth out this afternoon. 我今天下午拔了顆牙。have用作實義動詞時不能使用縮略式。詞組have to有情態(tài)意義，詳見“情態(tài)動詞”。9.4 do的形式和用法助動詞do有五種形式：肯定式 否定式 縮略否定式原形 do do not dont 現(xiàn)在式第三人稱單數(shù) does does not doesnt過去式 did did not didntdid not注 do用作實義動詞時有現(xiàn)在分詞doing和過去分詞don

14、e。助動詞do的主要用法是：1）構(gòu)成現(xiàn)在一般時和過去一般時的疑問句。如：（1）Do you always carry an umbrella? 你經(jīng)常帶傘嗎？（2）Did everything come off all right? 一切都進(jìn)行得順利嗎？2）構(gòu)成現(xiàn)在一般時和過去一般時的否定句。如：（3）She didnt cool down for hours after that argument. 在那場爭辯之后，她好幾個小時都沒平靜下來。（4）Dont worry, he will be brought to book for his wickedness one day. 別擔(dān)心，他的

15、惡行總有一天受到懲罰的。注如用其它時態(tài)，疑問句的助動詞須提至主語前，否定句的助動詞之后加not。如：Will he be able to hear at such a distance? 離這么遠(yuǎn)，他會聽得到嗎？You havent been abroad before, have you? 你以前沒出過國，是嗎？3）用于替代，以避免重復(fù)。如：（5）May I come round in the morning? 上午我可以來拜訪你嗎？Yes, please do. 可以，請來吧。（do替代come round）（6）I dont like coffee and neither does my

16、 wife. 我不喜歡咖啡，我妻子也不喜歡。（does替代like）4）用于強(qiáng)調(diào)。如：（7）My parents think I didnt study for my exams, but I did study. 我爸爸媽媽認(rèn)為我考試前沒有復(fù)習(xí)，但我是復(fù)習(xí)了。（8）Although I have little time for entertainment, I do go to the theatre once in a while. 雖然我很少時間娛樂，但我還是間或去看戲。（9）Were very pleased that she does intend to come. 她的確打算來，我

17、們非常高興。（10）The letter we were expecting never did arrive. 我們期待的信一直沒有到。（11）Do you remember how kind she was? 你記得她多友善嗎？I certainly do remember. 當(dāng)然記得。5）用于懇求。如：（12）Do come to the party tonight. 務(wù)請今晚來參加晚會。（13）Do be quiet! 請別作聲！此外，do還可用作實義動詞，意謂“做”、“干”等等。如：（14）Shes doing her knitting. 她正在紡織衣物。（15）She interr

18、upted him before his speech was done. 她不等他把話說完就打斷了他。（16）Bad books do great harm. 壞書有很大害處。（17）Will you do me a favour? 你愿幫我個忙嗎？（18）Jane is doing the dishes. 珍妮正在洗碟子。（19）I will do my best. 我愿盡力而為。（20）That will do. 行了（或夠了）。9.5 shall(should)和will(would)的形式和用法助動詞shall(過去式should)和will(過去式would)有下列幾種形式：肯定式

19、 縮略肯定式 否定式 縮略否定式shall ll shall not shant should should not shouldntwill ll will not wontll notwould d would not wouldntd not助動詞shall(should)和will(would)可用于構(gòu)成各種將來和過去將來時態(tài)，shall(should)用于第一人稱，will(would) 用于第二人稱、第三人稱。當(dāng)代英語（尤其是美國英語中），will(would)常用于一切人稱。1）shall用于各種將來時態(tài)的第一人稱（當(dāng)代英語多用will）。如：（1）We shall be goi

20、ng away tomorrow by an early train. 我們將于明日搭早班車離開。（2）I shall let you know as soon as I have heard from them. 我一俟接到他們的信，立即告訴你。2）should用于各種過去將來時態(tài)的第一人稱（當(dāng)代英語多用would）。如：（3）So this was the place where I should study for the three years. It made a bad first impression. （4）The BBC weather report this morning

21、 said that we should have rain. 英國廣播公司今晨的天氣預(yù)報說，我們這兒將有雨。3）will用于各種將來時態(tài)的第二、第三人稱。如：（5）They will be looking for anyone connected with her. 他們將尋找每一個與她有往來的人。（6）The play is coming off in AugustBy then the play will have been running for three months. 這個劇將于八月停演到那時它將連演三個月了。4）would用于各種過去將來時態(tài)的第二、第三人稱。如：（7）They

22、 said it would be fine. 他們說天氣會很好。（8）They would have finished by five oclock. 他們將于五時前完工。shall(should)和will(would)可用作情態(tài)動詞，詳見“情態(tài)動詞”。should和would可以構(gòu)成虛擬語氣，詳見“虛擬語氣”。二、情態(tài)動詞9.6 情態(tài)動詞的含義和特征情態(tài)動詞只有情態(tài)意義，即它所表示的是說話人對動作的觀點(diǎn)，如需要、可能、意愿或懷疑等。情態(tài)動詞有以下特征：1）在形式上，情態(tài)動詞沒有實義動詞的各種變化，只有could，would，had to，was(或were) to，might等幾個過去式

23、。其它如must，ought to等的過去皆與現(xiàn)在式同形。2）在意義上，大多數(shù)情態(tài)動詞有多個意義。如can可表“能夠”、“可能”、“允許”等，many可表“可能”、“ 允許”、“目的”、“讓步”等。3）在用法上，情態(tài)動詞與助動詞一樣，須后接動詞原形，構(gòu)成謂語動詞。9.7 can(could) 的形式和用法can(could)有下列幾種形式：肯定式 否定式 縮略否定式現(xiàn)在式 can cannot cant過去式 could could not couldnt注在美國英語中往往用can not替代cannot。can是現(xiàn)在式，多用在指現(xiàn)在或?qū)?。如：?）He can speak English.

24、 他能說英語嗎？（2）Can you come to the meeting? 你能來開會嗎？could是過去式，多用于指過去。如：（3）He could speak English when he was a child. 他小時就能說英語了。但could亦可用于指現(xiàn)在，表虛擬語氣，或作為can的委婉形式。如：（4）That man could do with a haircut. 那人需要理個發(fā)了。（表現(xiàn)在）（5）If I could go, I should be glad. 假如我能去，那我就會很高興。（表虛擬語氣）（6）Could I help you? 我能幫你干點(diǎn)什么嗎？（比Ca

25、n I help you? 委婉）can(could)的基本用法是：1）表能夠。如：（7）I can lift this stone. 我能舉起這塊石頭。（表體能）（8）Can you use chopsticks? 你能用筷子嗎？（表技能）（9）I can see him tonight. 我今晚能見到他。（表可能）can表能夠時與短語be able to同義，但后者可用于各種時態(tài)。can表能夠時可用于各種句式。如：（10）She can play a few simple tunes on the piano. 她能在鋼琴上彈一些簡單的調(diào)子。（肯定句）（11）Can you write w

26、ith your left hand? 你能用左手寫字嗎？（疑問句）（12）I can not promise you anything. 我不能答應(yīng)你任何事。（否定句）can亦可指將來。如：（13）We can discuss your paper after lunch. 午飯后我們能討論你的論文。如需要強(qiáng)調(diào)將來時間時，則可用短語shall/will be able to。如：（14）I shall be able to earn my own living soon. 我很快就能自立了。（15）He says hell be able to be home for Christmas.

27、他說他能回家過圣誕節(jié)。could主要指過去。如：（16）I said that I could go. 我說我能去。（17）Could the boy read before he went to school? 這男孩上學(xué)前能識字嗎？單純敘述過去事實時，最好用was或were+able。如：（18）I was able to help you yesterday. 我昨天能幫你的。但could也?？芍脯F(xiàn)在或?qū)怼Ｈ纾海?9）You could phone her, I suppose. 我看你可以給她打電話。（20）The river could easily overflow, could

28、nt it? 河水可能容易泛濫，不是嗎？如could與動詞原形的完成式連用，則指過去未實現(xiàn)的動作。如：（21）She could have explained the mystery. 她本能夠解釋這個秘密的。（實際上未解釋）2）表可能。如：（22）The moon cannot always be at the full. 月不可能常圓。（23）If its raining tomorrow, the sports can take place indoors. 如果明天下雨，運(yùn)動會就可能在室內(nèi)舉行。 can表可能時可指現(xiàn)在或?qū)怼Ｈ纾海?4）You can perhaps obtain a

29、 dog from the Dogs Home. 你也許可以從養(yǎng)狗場弄到一條狗。（肯定句）（25）What can he mean? 他可能是什么意義呢？（疑問句）（26）We cant use the indefinite article with this noun. 我們不可以在這個名詞前用不定冠詞。（否定句）表可能時，could可指過去。如：（27）He said he couldnt agree more. 他說他再同意不過了。could亦可指現(xiàn)在或?qū)?，表虛擬語氣。如：（28）It could be my mother. 可能是我母親。（29）He could arrive tom

30、orrow. 他可能明天到。could與完成式連用，則指過去未實現(xiàn)的動作。如：（30）It could have been seen from here if it had not been so dark. 如果天不那么黑，你可能從這兒望見它的。（實際上已望不見）3）表允許。如：（31）You can borrow my bike tomorrow. 明天你可以借用我的自行車。表這個意義時，can用于疑問句時表要求，用于否定句時表不許。如：（32）Can you lend me a hand? 你能幫我一把嗎？（33）This sort of thing cant go on! 這類事不能再

31、繼續(xù)了！could指現(xiàn)在時，僅用于疑問句表更委婉的要求。如：（34）Could I interrupt a moment? 我可以插句話嗎？但這種表允許的用法可用于間接引語。如：（35）Father said I could swim in the river. 爸爸說我可以在河里游泳。4）表懷疑。如：（36）Can it be true? 那會是真的嗎？表這個意義時，can僅用于一般疑問句，并有感情色彩。can用于一般式，表現(xiàn)在。如：（37）Can he really be ill? 你真的會病嗎？can用于進(jìn)行式，表將來。如：（38）Can he be making the investi

32、gation all alone? 他會獨(dú)立進(jìn)行調(diào)查嗎？can用于完成式，表過去。如：（39）Can she have told a lie? 她會說謊嗎？can用于完成式或完成進(jìn)行式時亦可表持續(xù)的動作。如：（40）Can she really have been at home all this time? 她真的會一直在家嗎？（41）Can she have been waiting for us so long? 她會等我們這么久嗎？could指現(xiàn)在時亦可有這些用法，但暗含著更不確定的意義。如：（42）Could it be true? （43）Could she be telling

33、lies? （44）Could he have said it? （45）Could he have been at home all this time? （46）Could she have been waiting for us so long?5）cant表不大可能。如：（47）It cant be true. 那不大可能是真的。cant會有感情色彩。如：（48）He cant be really ill. 他不大可能真的病了。（指現(xiàn)在）（49）She cant be telling lies. 她不大可能說謊。（指現(xiàn)在）（50）He cant have said it. 他不大可能說

34、這種話。（指過去）（51）She cant have been at home all this time. 她不大可能一直在家。（指過去）（52）She cant have been waiting for us so long. 她不大可能等我們這么久。（指過去）could亦可有這些用法，但語氣委婉。如：（53）It couldnt be true. （54）She couldnt be telling lies.（55）He couldnt have said it.（56）She couldnt have been at home all this time. （57）She coul

35、dnt have been waiting for us so long. 6）can和could用于特殊疑問句，有感情色彩，表驚訝、迷惑等。如：（58）What can(could) he mean? 他可能是什么意義呢？（59）What can(could) he be doing? 他可能在干什么呢？（60）What can(could) he have done? 他可能干什么了呢？（61）Where can(could) he have gone to? 他可能去哪里了呢？7）can與could的比較：can與could表能夠與可能時，can表真實，could表非真實。如：（62）H

36、e can speak English. 他能說英語。（表能夠）（63）He could speak English if necessary. 他在必要時能說英語。（64）You can get the book from the library. 你可以從圖書館借到這本書。（表可能）（65）You could get the book from the library if necessary. 你在必要時可從圖書館借到這本書。表允許和推測時，只是could語氣較為委婉，含義較不確定。如：（66）Can I use your pen? 我可以借用你的筆嗎？（表允許）（67）Could I

37、use your pen? （較為委婉）（68）Can it be true? 那可能是真的嗎？（表推測）（69）Could it be true? （較不確定）（70）It cant be true. 那不大可能是真的。（表不大可能）（71）It couldnt be true. （較不確定）8）用于固定習(xí)語。如：（72）She cant help crying. 她不禁哭起來。（73）He couldnt help laughing. 他不禁笑起來。（74）I cant but ask him about it. 關(guān)于這件事我只得問他。（75）They couldnt but refuse

38、 him. 他們不得不拒絕他。9.8 may(might)的形式和用法may(might)有下列幾種形式：肯定式 否定式 縮略否定式現(xiàn)在式 may may not maynt過去式 might might not mightnt注 maynt比較少見。may是現(xiàn)在式，多指現(xiàn)在。如：（1）It may be true? 那可能是真的。might是may的過去式，可用于指過去。如：（2）He told me that it might be true. 他告訴過我那可能是真的。亦可用于指現(xiàn)在，但語氣較為緩和、委婉，含義更不確定，或表虛擬語氣。如：（3）It might be true? 那可能是真

39、的。（4）Might I come and see you? 我可以來看你嗎？ may(might)的基本用法是：1） 表可能，暗含不確定，等于possibly，perhaps或maybe。如：（5）He may be busy getting ready for his trip. 他也許在忙于準(zhǔn)備外出旅行。may表可能時，可用于肯定句和否定句。如：（6）He may be at home. 他也許在家。（7）He may not be at home. 他也許不在家。may表可能時，常指將來。如：（8）He may come soon. 他也許馬上就來。may也可指現(xiàn)在。如：（9）He m

40、ay not know about it. 他也許不知道這件事。（10）I never see him about now. For all I know, he may be writing a book. 我近來從未見他來著。就我所知，他也許在寫書。may用于完成式時指過去。如：（11）You may have been some account of the matter. 你也許讀到過關(guān)于這件事的一些報道。may用于完成式或完成進(jìn)行時亦可指持續(xù)的動作。如：（12）He may have been at home for about two hours. 他也許在家待了兩小時了。（13）

41、He may have been waiting for us for an hour. 他也許等我們一小時了。might表可能時亦可有這些用法，與may的區(qū)別在于它的含義更不確定。如：（14）He might come soon. 他也許馬上就會來的。（15）He might be ill. 他也許生病了吧。（16）He might be doing his lessons now. 他也許正在做功課吧。（17）He might have spoken to her yesterday. 他昨天也許同她說過話吧。2）表允許。如：（18）The director is alone now. S

42、o you may see him now. 局長現(xiàn)在是獨(dú)自一人，所以你可以現(xiàn)在去見他。表這個意義時，may可用于肯定句和疑問句，亦可用于否定句但不太常用。如：（19）You may smoke in here. 你可以在這兒抽煙。（20）May I smoke in here? 我可以在這兒抽煙嗎？（21）You may not smoke in here. 你不可在這兒抽煙。may表允許時僅用于一般式。might用于疑問句，語氣更委婉。如：（22）Might I join you? 我可以參加你們一道嗎？might亦可用于間接引語。如：（23）He told me that I might

43、 smoke in the room. 他告訴我可以在房間里抽煙。3）表責(zé)備，只用might，用于肯定句?？捎糜谝话闶胶屯瓿墒?，后者則表未實現(xiàn)的動作。如：（24）You might ask before you borrow my car. 你可以先問問我再借我的車子嘛。（25）You might have helped me. 你滿可以幫我一把嘛。4）may與might的比較：might可表虛擬語氣，may則不可。如：（26）It might help a little if you would only keep clean. 你只要愿意保持清潔，情況或許就會好一些。在多數(shù)情況下，migh

44、t比may語氣更為緩和委婉，含義更不確定。如：（27）May I speak to him now?（28）Might I speak to him now?（29）H（26）e may come a little later. （30）He might come a little later. 表可能時只用may指現(xiàn)在，一般不用might指過去，might只用于間接引語中。表責(zé)備時則只用might。如：（31）You may find the book at the library. 你可以在圖書館找到這本書。（32）You might have considered your parent

45、s feelings. 你本可考慮你父母的感情嘛。5）用于固定習(xí)語。如：（33）You may as well give him the letter. 你還是把信給他為好。（34）I might as well stay at home tonight. 我今晚還是待在家里吧。（35）His appearance has changed so much that you may well not recognize him. 他的外貌變化很大，你很可能認(rèn)不出他來。（36）Roy Wilson, the new doctor, was twenty-eight, large, heavy, m

46、ature and blond. He might have been a Scandinavian sailor. 羅伊威爾遜是新來的醫(yī)生，28歲，身高體重，發(fā)育成熟，頭發(fā)金黃，簡直像個斯堪的納維亞水手。6）may可用于某些賓語從句和目的、讓步狀語從句。如：（37）I fear he may fall ill. 我恐怕他會生病。（用于賓語從句）（38）He is coming here so that they may discuss it without delay. 他就要到這里來，這樣他們可能立即討論那件事。（用于目的狀語從句）（39）However cold it may be, w

47、ell go skiing. 天不管多冷，我們都要去滑雪。（用于讓步狀語從句）7）can與may的比較：can與may只有在表可能和允許時意義相同。但在這種情況下，它們也不能隨意互換：表可能時，may僅用于肯定句，而can則可用于各種句式。如：（40）He may find this book at the library. 他可以在圖書館找到這本書。（may用于肯定句）（41）He can find this book at the library. 他可以在圖書館找到這本書。（can用于肯定句）（42）Can he find this book at the library? 他能在圖書館

48、找到這本書嗎？（can用于疑問句）（43）He cannot find this book at the library. 他不可能在圖書館找到這本書。（can用于否定句）表允許時，二者意義無甚區(qū)別，只有may較正式些，而can則較口語化。如：（44）May I speak to you for a moment, professor? 我可以跟你談一會兒嗎，教授？（45）Can I have a cup of tea, mother? 我可以喝杯茶嗎，媽媽？9.9 must的形式和用法must只有一種形式，其現(xiàn)在式與過去式同形?？隙ㄊ?否定式 縮略否定式must must not mustn

49、t它可指現(xiàn)在或?qū)恚糜谕瓿墒綍r則可指過去，其過去式僅用于間接引語。must的基本用法是：1）表義務(wù)。如：（1）You must talk to your daughter about her future. 你必須跟你的女兒談?wù)勊那巴尽＃?）Must he do it himself. 他必須親自干那事嗎？表這個意義時，must用于一般式，并用于肯定句和疑問句。2）在否定結(jié)構(gòu)中表示不許。如：（3）He must not leave his room. 他不許離開他的房間。表這個意義時，must用于一般式。3）表堅定的建議。如：（4）You must come and see us when

50、 youve in London. 你到倫敦后應(yīng)當(dāng)來看看我們。（5）You mustnt miss the film. It is very good. 你不可錯過那個影片。它很好看。表這個意義時，must用于一般式，用于肯定句和否定句。4）表推測，暗含很大的可能性。如：（6）He must be ill. He looks so pale. 他一定是病了。他的臉色蒼白。（7）It must be late as the streets are deserted. 時間一定很晚了，街上已空無一人。表這個意義時，must僅用于肯定句，不能用于疑問句或否定句。它可以用于不同時式，僅可指現(xiàn)在，動態(tài)動

51、詞則用于進(jìn)行式。如：（8）Lets have something to eat. You must be starving. 我們吃點(diǎn)東西吧。你一定餓了。5）可用于不同時式，表不同意義。表義務(wù)。如：（9）You must stay here. 你必須待在這兒。亦可表推測。如：（10）He must be over fifty. 他一定有五十開外了。must可用于完成式，指過去。如：（11）It is six oclock. She must have come home. 現(xiàn)在是六點(diǎn)，她一定到家了。must用于完成進(jìn)行時，可表持續(xù)的動作。如：（12）It must have been rain

52、ing all the night. There are big puddles in the garden. 雨一定是下了整整一夜，花園里有大片大片的水。（13）He must have been here since breakfast. 早飯后他一定是在這兒。6）用于間接引語，表過去。如：（14）He said he must go. 他說他必須去。7）用于固定習(xí)語。如：（15）He must needs go there. 他偏偏要去那兒。8）must與may的比較。二者均可表推測，但側(cè)重點(diǎn)不一樣：may暗含不確定，must暗含很可能。如：（16）For all I know, he

53、may be an actor. His face seems so familiar. 就我所看，他可能是個演員，他似乎很面熟。（17）He must be an actor. His voice carries so well. 他一定是個演員，他的聲音很洪亮。may和must均可用于否定句，表不許，但may較少用。對may表要求時的否定回答，一般用must not或cannot。如：（18）May I smoke here? 我可以在這兒抽煙嗎？No, you mustnt(cant). 不，不行。9.10 have to的形式和用法詞組have to也是情態(tài)動詞。它由have +to組

54、成，因此具有have的各種時式。如：（1）He is an invalid and has to have a nurse. 他是個病弱之人，需要護(hù)士照顧。（2）She know what she had to do. 她知道她需要做什么。（3）I shall have to reconsider my position. 我將不得不重新考慮我的立場。（4）He is always having to exercise judgment. 他經(jīng)常需要進(jìn)行判斷。（5）My impression was that he was having to force himself to talk. 我的

55、印象是，他需要強(qiáng)使自己說話。（6）I have had to remind you of writing to her all this time. 我不得不老提醒你寫信給她。（7）The people had had to be told that an experiment was taking place that day. 必須通知人們，那天將進(jìn)行試驗。（8）“As a matter of fact,” he said, “Ive been having to spend some time with the research people.” “事實上，”他說，“我必須一直同研究人員

56、一起待一些時間?！保?）It wouldnt have been very nice for the Davidsons to have to mix with all those people in the smoking-room. 戴維森一家人非得與吸煙間的所有那些人混在一起，是不大好的事。（10）Having to work alone, he wanted all his time for his research. 他必須單干，所以他想把他的全部時間投入研究工作。have to的疑問和否定結(jié)構(gòu)多用助動詞do構(gòu)成。如：（11）Why do I have to do everything? 為什么事事都得我干？（12）Did he have to tell them about it? 他必須把那件事告訴他們嗎？（13）You dont have to explain. 你不必作解釋了。（14）There was a grin on his face. He did not have to tell me that he already knew. 他咧嘴而笑。他不需要告訴我他已知道了。have to的基本用法是：1）表客觀的義務(wù)或需要?？捎糜诟鞣N句式，但只用于一般式。如：（15）He had to do it. 他